4 files changed, 57 insertions, 95 deletions

diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index ee166c586642..1ccb188ba40d 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -339,3 +339,8 @@ void __init kexec_setup(void)
 {
         export_htab_values();
 }
+
+int overlaps_crashkernel(unsigned long start, unsigned long size)
+{
+        return (start + size) > crashk_res.start && start <= crashk_res.end;
+}
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 4ca608c9cd72..a04f726d3bab 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -50,6 +50,7 @@
 #include <asm/machdep.h>
 #include <asm/pSeries_reconfig.h>
 #include <asm/pci-bridge.h>
+#include <asm/kexec.h>
 
 #ifdef DEBUG
 #define DBG(fmt...) printk(KERN_ERR fmt)
@@ -836,6 +837,42 @@ static unsigned long __init unflatten_dt_node(unsigned long mem,
         return mem;
 }
 
+static int __init early_parse_mem(char *p)
+{
+        if (!p)
+                return 1;
+
+        memory_limit = PAGE_ALIGN(memparse(p, &p));
+        DBG("memory limit = 0x%lx\n", memory_limit);
+
+        return 0;
+}
+early_param("mem", early_parse_mem);
+
+/*
+ * The device tree may be allocated below our memory limit, or inside the
+ * crash kernel region for kdump. If so, move it out now.
+ */
+static void move_device_tree(void)
+{
+        unsigned long start, size;
+        void *p;
+
+        DBG("-> move_device_tree\n");
+
+        start = __pa(initial_boot_params);
+        size = initial_boot_params->totalsize;
+
+        if ((memory_limit && (start + size) > memory_limit) ||
+                        overlaps_crashkernel(start, size)) {
+                p = __va(lmb_alloc_base(size, PAGE_SIZE, lmb.rmo_size));
+                memcpy(p, initial_boot_params, size);
+                initial_boot_params = (struct boot_param_header *)p;
+                DBG("Moved device tree to 0x%p\n", p);
+        }
+
+        DBG("<- move_device_tree\n");
+}
 
 /**
  * unflattens the device-tree passed by the firmware, creating the
@@ -1070,6 +1107,7 @@ static int __init early_init_dt_scan_chosen(unsigned long node,
                 iommu_force_on = 1;
 #endif
 
+        /* mem=x on the command line is the preferred mechanism */
         lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
         if (lprop)
                 memory_limit = *lprop;
@@ -1123,17 +1161,6 @@ static int __init early_init_dt_scan_chosen(unsigned long node,
 
         DBG("Command line is: %s\n", cmd_line);
 
-        if (strstr(cmd_line, "mem=")) {
-                char *p, *q;
-
-                for (q = cmd_line; (p = strstr(q, "mem=")) != 0; ) {
-                        q = p + 4;
-                        if (p > cmd_line && p[-1] != ' ')
-                                continue;
-                        memory_limit = memparse(q, &q);
-                }
-        }
-
         /* break now */
         return 1;
 }
@@ -1297,11 +1324,6 @@ void __init early_init_devtree(void *params)
         strlcpy(saved_command_line, cmd_line, COMMAND_LINE_SIZE);
         parse_early_param();
 
-        lmb_enforce_memory_limit(memory_limit);
-        lmb_analyze();
-
-        DBG("Phys. mem: %lx\n", lmb_phys_mem_size());
-
         /* Reserve LMB regions used by kernel, initrd, dt, etc... */
         lmb_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
 #ifdef CONFIG_CRASH_DUMP
@@ -1309,6 +1331,15 @@ void __init early_init_devtree(void *params)
 #endif
         early_reserve_mem();
 
+        lmb_enforce_memory_limit(memory_limit);
+        lmb_analyze();
+
+        DBG("Phys. mem: %lx\n", lmb_phys_mem_size());
+
+        /* We may need to relocate the flat tree, do it now.
+         * FIXME .. and the initrd too? */
+        move_device_tree();
+
         DBG("Scanning CPUs ...\n");
 
         /* Retreive CPU related informations from the flat tree
@@ -2058,29 +2089,3 @@ int prom_update_property(struct device_node *np,
         return 0;
 }
 
-#ifdef CONFIG_KEXEC
-/* We may have allocated the flat device tree inside the crash kernel region
- * in prom_init. If so we need to move it out into regular memory. */
-void kdump_move_device_tree(void)
-{
-        unsigned long start, end;
-        struct boot_param_header *new;
-
-        start = __pa((unsigned long)initial_boot_params);
-        end = start + initial_boot_params->totalsize;
-
-        if (end < crashk_res.start || start > crashk_res.end)
-                return;
-
-        new = (struct boot_param_header*)
-                __va(lmb_alloc(initial_boot_params->totalsize, PAGE_SIZE));
-
-        memcpy(new, initial_boot_params, initial_boot_params->totalsize);
-
-        initial_boot_params = new;
-
-        DBG("Flat device tree blob moved to %p\n", initial_boot_params);
-
-        /* XXX should we unreserve the old DT? */
-}
-#endif /* CONFIG_KEXEC */
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 078fb5533541..a52377c68fc6 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -194,8 +194,6 @@ static int __initdata of_platform;
 
 static char __initdata prom_cmd_line[COMMAND_LINE_SIZE];
 
-static unsigned long __initdata prom_memory_limit;
-
 static unsigned long __initdata alloc_top;
 static unsigned long __initdata alloc_top_high;
 static unsigned long __initdata alloc_bottom;
@@ -594,16 +592,6 @@ static void __init early_cmdline_parse(void)
         }
 #endif
 
-        opt = strstr(RELOC(prom_cmd_line), RELOC("mem="));
-        if (opt) {
-                opt += 4;
-                RELOC(prom_memory_limit) = prom_memparse(opt, (const char **)&opt);
-#ifdef CONFIG_PPC64
-                /* Align to 16 MB == size of ppc64 large page */
-                RELOC(prom_memory_limit) = ALIGN(RELOC(prom_memory_limit), 0x1000000);
-#endif
-        }
-
 #ifdef CONFIG_KEXEC
         /*
          * crashkernel=size@addr specifies the location to reserve for
@@ -1115,29 +1103,6 @@ static void __init prom_init_mem(void)
         }
 
         /*
-         * If prom_memory_limit is set we reduce the upper limits *except* for
-         * alloc_top_high. This must be the real top of RAM so we can put
-         * TCE's up there.
-         */
-
-        RELOC(alloc_top_high) = RELOC(ram_top);
-
-        if (RELOC(prom_memory_limit)) {
-                if (RELOC(prom_memory_limit) <= RELOC(alloc_bottom)) {
-                        prom_printf("Ignoring mem=%x <= alloc_bottom.\n",
-                                RELOC(prom_memory_limit));
-                        RELOC(prom_memory_limit) = 0;
-                } else if (RELOC(prom_memory_limit) >= RELOC(ram_top)) {
-                        prom_printf("Ignoring mem=%x >= ram_top.\n",
-                                RELOC(prom_memory_limit));
-                        RELOC(prom_memory_limit) = 0;
-                } else {
-                        RELOC(ram_top) = RELOC(prom_memory_limit);
-                        RELOC(rmo_top) = min(RELOC(rmo_top), RELOC(prom_memory_limit));
-                }
-        }
-
-        /*
          * Setup our top alloc point, that is top of RMO or top of
          * segment 0 when running non-LPAR.
          * Some RS64 machines have buggy firmware where claims up at
@@ -1149,9 +1114,9 @@ static void __init prom_init_mem(void)
                 RELOC(rmo_top) = RELOC(ram_top);
         RELOC(rmo_top) = min(0x30000000ul, RELOC(rmo_top));
         RELOC(alloc_top) = RELOC(rmo_top);
+        RELOC(alloc_top_high) = RELOC(ram_top);
 
         prom_printf("memory layout at init:\n");
-        prom_printf("  memory_limit : %x (16 MB aligned)\n", RELOC(prom_memory_limit));
         prom_printf("  alloc_bottom : %x\n", RELOC(alloc_bottom));
         prom_printf("  alloc_top    : %x\n", RELOC(alloc_top));
         prom_printf("  alloc_top_hi : %x\n", RELOC(alloc_top_high));
@@ -1348,16 +1313,10 @@ static void __init prom_initialize_tce_table(void)
 
         reserve_mem(local_alloc_bottom, local_alloc_top - local_alloc_bottom);
 
-        if (RELOC(prom_memory_limit)) {
-                /*
-                 * We align the start to a 16MB boundary so we can map
-                 * the TCE area using large pages if possible.
-                 * The end should be the top of RAM so no need to align it.
-                 */
-                RELOC(prom_tce_alloc_start) = _ALIGN_DOWN(local_alloc_bottom,
-                                                          0x1000000);
-                RELOC(prom_tce_alloc_end) = local_alloc_top;
-        }
+        /* These are only really needed if there is a memory limit in
+         * effect, but we don't know so export them always. */
+        RELOC(prom_tce_alloc_start) = local_alloc_bottom;
+        RELOC(prom_tce_alloc_end) = local_alloc_top;
 
         /* Flag the first invalid entry */
         prom_debug("ending prom_initialize_tce_table\n");
@@ -2265,10 +2224,6 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4,
         /*
          * Fill in some infos for use by the kernel later on
          */
-        if (RELOC(prom_memory_limit))
-                prom_setprop(_prom->chosen, "/chosen", "linux,memory-limit",
-                             &RELOC(prom_memory_limit),
-                             sizeof(prom_memory_limit));
 #ifdef CONFIG_PPC64
         if (RELOC(ppc64_iommu_off))
                 prom_setprop(_prom->chosen, "/chosen", "linux,iommu-off",
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 6224624c3d38..59773d9044ba 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -347,9 +347,6 @@ void __init setup_system(void)
 {
         DBG(" -> setup_system()\n");
 
-#ifdef CONFIG_KEXEC
-        kdump_move_device_tree();
-#endif
         /*
          * Unflatten the device-tree passed by prom_init or kexec
          */